package test.test02;

import java.util.HashMap;
import java.util.Hashtable;
import java.util.concurrent.ConcurrentHashMap;

public class Hash {
    public static void main(String[] args) {
        HashMap<String,Integer> map = new HashMap<>();
        Hashtable<String,Integer> table = new Hashtable<>();
        ConcurrentHashMap<String,Integer> concurrentMap = new ConcurrentHashMap<>();
    }
}
